How did I get fitting of boards wrong

[yoshi]

What did I do wrong when I fitted my wood in the rear? I looked at this page- http://www.classicheartbeat.com/bed_wood.htm . I copied this part- The following is a picture of the cross section and dimensions of the groove pattern that GM used when milling the boards. When I did that there wasn't any gap between the boards. I want to get it right as I'm getting some oak, thanks

[Baddflash]

Those groove dimensions do not match the factory specs, look at mar-k's website the groove dimensions there are correct.

http://67-72chevytrucks.com/vboard/s...d.php?t=362270

I compare the two different specs against an original piece here

[58CameoAZ]

You weren't using a Metric Ruler were you? All Kidding aside, i used the same chart
but its for the 55-59 stepside trucks and it was dead on.
are you sure you copied the right year for your truck?
their should be just enough of a Gap for the Carriage bolts to be between the rails
are the outside boards all the way under the bed strip rails? (that is if your year is like that of the 55-59 TF trucks as i am note familiar with your year of truck)
Good luck Sir,
Alen

[yoshi]

Hi Alen, I have a 49 but I'm gonna be using 8 boards not 9 due to only having 7 metal strips powder coated black

[mr48chev]

Mar-K doesn't give an exact board width for "their" boards but the measurements are for 1/2 inch gaps between the boards while I'd think the ones on Classic Heartbeat are for more like a 3/8 gap. You don't want the boards butt up against each other or butt up against the bolts as that won't leave any room for swelling or shrinking. That isn't as big a deal with most show only trucks but could be a big issue with a daily driver that gets wet more often.

As long as you didn't cut all the boards too narrow you should be fine. lay in the outside boards and the ones next to them and lay the strips on them and go until you get to the last board. leave everything loose so you can do some adjusting and then see if you have to modify the last board to get things to work. If you do have to alter the last board a bit only you will know and anyone that figures it out is looking way too close anyhow.

[Baddflash]

I used the lengths and widths listed on classic heartbeat or gmc Paul's page, I milled the groves according to the specs on mar-k' page and they match the original boards exactly.

[yoshi]

I used pine in case I made any mistakes, the boards were touching each other due to the measurements of the milled part. I had to replace the last board with a wider one.

[joedoh]

ok do me a favor, measure all your boards and list their sizes. if you used the 8 board setup on that link, it should come out to 47.5" or 51" when adding a 1/2 inch for each strip. The 9 board system also comes out to 47" or 51" total adding 1/2 inch for each strip.

then measure your bed. should be roughly 51" across.

[yoshi]

While I'm waiting on parts for the front end I've pulled the wood out to sort it out. Am I right in saying that the front cross member is loose (not fitted to frame)?

[yoshi]

Rear cross member will have to be modified as it encroaches on the filler neck

[oldman3]

Yoshi, here a couple pics from the bed manual I have hope this helps. See #4 front cross sill first pic..Jim

[yoshi]

Ah thank you, as I thought #2 cross sill is unique & not fixed to the frame,